scholarly journals Scaling of thermal tolerance with body mass and genome size in ectotherms: A comparison between water-and air-breathers

2019 ◽  
Author(s):  
Félix P. Leiva ◽  
Piero Calosi ◽  
Wilco C.E.P. Verberk
Keyword(s):  
Genome Size ◽  
Body Mass ◽  
Thermal Tolerance ◽  
Oxygen Limitation ◽  
Thermal Limits ◽  
Interspecific Differences ◽  
Extinction Events ◽  
Experimental Trials ◽  
Methodological Aspects

AbstractGlobal warming appears to favour smaller-bodied organisms, but whether larger species are also more vulnerable to thermal extremes, as suggested for past mass-extinction events, is still an open question. Here, we tested whether interspecific differences in thermal tolerance (heat and cold) of ectotherm organisms are linked to differences in their body mass and genome size (as a proxy for cell size). Since the vulnerability of larger, aquatic taxa to warming has been attributed to the oxygen limitation hypothesis, we also assessed how body mass and genome size modulate thermal tolerance in species with contrasting breathing modes, habitats and life-stages. A database with the upper (CTmax) and lower (CTmin) critical thermal limits and their methodological aspects was assembled comprising more than 500 species of ectotherms. Our results demonstrate that thermal tolerance in ectotherms is dependent on body mass and genome size and these relationships became especially evident in prolonged experimental trials where energy efficiency gains importance. During long-term trials, CTmax was impaired in larger-bodied water-breathers, consistent with a role for oxygen limitation. Variation in CTmin was mostly explained by the combined effects of body mass and genome size and it was enhanced in larger-celled, air-breathing species during long-term trials, consistent with a role for depolarization of cell membranes. Our results highlight the importance of accounting for phylogeny and exposure duration. Especially when considering long-term trials, the observed effects on thermal limits are more in line with the warming-induced reduction in body mass observed during long-term rearing experiments.

scholarly journals Scaling of thermal tolerance with body mass and genome size in ectotherms: a comparison between water- and air-breathers

2019 ◽  
Vol 374 (1778) ◽  
pp. 20190035 ◽  
Author(s):  
Félix P. Leiva ◽  
Piero Calosi ◽  
Wilco C. E. P. Verberk
Keyword(s):  
Genome Size ◽  
Body Mass ◽  
Thermal Tolerance ◽  
Global Climate ◽  
Oxygen Limitation ◽  
Thermal Limits ◽  
Physiological Diversity ◽  
Interspecific Differences ◽  
Extinction Events

Global warming appears to favour smaller-bodied organisms, but whether larger species are also more vulnerable to thermal extremes, as suggested for past mass-extinction events, is still an open question. Here, we tested whether interspecific differences in thermal tolerance (heat and cold) of ectotherm organisms are linked to differences in their body mass and genome size (as a proxy for cell size). Since the vulnerability of larger, aquatic taxa to warming has been attributed to the oxygen limitation hypothesis, we also assessed how body mass and genome size modulate thermal tolerance in species with contrasting breathing modes, habitats and life stages. A database with the upper (CTmax) and lower (CTmin) critical thermal limits and their methodological aspects was assembled comprising more than 500 species of ectotherms. Our results demonstrate that thermal tolerance in ectotherms is dependent on body mass and genome size and these relationships became especially evident in prolonged experimental trials where energy efficiency gains importance. During long-term trials, CTmax was impaired in larger-bodied water-breathers, consistent with a role for oxygen limitation. Variation in CTmin was mostly explained by the combined effects of body mass and genome size and it was enhanced in larger-celled, air-breathing species during long-term trials, consistent with a role for depolarization of cell membranes. Our results also highlight the importance of accounting for phylogeny and exposure duration. Especially when considering long-term trials, the observed effects on thermal limits are more in line with the warming-induced reduction in body mass observed during long-term rearing experiments. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

scholarly journals Effects of long-term preservation on amphibian body conditions: implications for historical morphological research

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3805 ◽  
Author(s):  
Guocheng Shu ◽  
Yuzhou Gong ◽  
Feng Xie ◽  
Nicholas C. Wu ◽  
Cheng Li
Keyword(s):  
Body Mass ◽  
Body Length ◽  
Historical Data ◽  
The Body ◽  
Morphological Data ◽  
Anuran Species ◽  
Interspecific Differences ◽  
Morphological Research ◽  
Long Term Preservation

Measurements of historical specimens are widely applied in studies of taxonomy, systematics, and ecology, but biologists often assume that the effects of preservative chemicals on the morphology of amphibian specimens are minimal in their analyses. We compared the body length and body mass of 182 samples of 13 live and preserved (up to 10 years) anuran species and found that the body length and body mass of preserved specimens significantly decreased by 6.1% and 24.8%, respectively, compared to those measurements of their live counterparts. The changes in body length and mass also exhibited highly significant variations between species. Similarly, there were significant differences in shrinkage of body length and body mass between sexes, where males showed greater shrinkage in body length and body mass compared to females. Preservation distorted the magnitude of the interspecific differences in body length observed in the fresh specimens. Overall, the reduction in body length or mass was greater in longer or heavier individuals. Due to the effects of preservation on amphibian morphology, we propose two parsimonious conversion equations to back-calculate the original body length and body mass of studied anurans for researchers working with historical data, since morphological data from preserved specimens may lead to incorrect biological interpretations when comparing to fresh specimens. Therefore, researchers should correct for errors due to preservation effects that may lead to the misinterpretation of results.

scholarly journals Effects of long-term preservation on amphibian body conditions: Implications for historical morphological research

2017 ◽  
Author(s):  
Guocheng Shu ◽  
Yuzhou Gong ◽  
Feng Xie ◽  
Nicholas C. Wu ◽  
Cheng Li
Keyword(s):  
Body Mass ◽  
Body Length ◽  
The Body ◽  
Morphological Data ◽  
Amphibian Species ◽  
Interspecific Differences ◽  
Males And Females ◽  
Morphological Research ◽  
Long Term Preservation

Measurements of historical specimens are widely applied in studies of taxonomy, systematics, and ecology, but biologists often assume that the effects of preservative chemicals on the morphology of amphibian specimens do not affect their analyses. We compared the body length and body mass of 14 live and preserved (up to 10 years) amphibian species and found that the body length and body mass of preserved specimens significantly decreased by 7.1% and 26.7%, respectively, compared to those measurements of their live counterparts. Additionally, there was greater body length (3.6%) and body mass (6.6%) shrinkage in the order Urodela than in the order Anura, but there were no significant differences in body length and body mass shrinkage between males and females. Furthermore, preservation apparently distorted the magnitude of the intersexual and interspecific differences in body length observed in the fresh specimens. When species were compared, we found that the shrinkage was proportionately greater in longer species, while the body mass of heavier individuals shrank proportionately less than that of lighter individuals. Due to the effects of preservation on amphibian morphology, we propose parsimonious conversion equations to back-calculate the original body length and body mass of study animals for researchers working with historical data because morphological data from preserved specimens may lead to incorrect biological interpretations. Therefore, researchers must correct for errors due to preservation effects that may lead to the misinterpretation of results.

scholarly journals Effects of long-term preservation on amphibian body conditions: Implications for historical morphological research

2017 ◽  
Author(s):  
Guocheng Shu ◽  
Yuzhou Gong ◽  
Feng Xie ◽  
Nicholas C. Wu ◽  
Cheng Li
Keyword(s):  
Body Mass ◽  
Body Length ◽  
The Body ◽  
Morphological Data ◽  
Amphibian Species ◽  
Interspecific Differences ◽  
Males And Females ◽  
Morphological Research ◽  
Long Term Preservation

Measurements of historical specimens are widely applied in studies of taxonomy, systematics, and ecology, but biologists often assume that the effects of preservative chemicals on the morphology of amphibian specimens do not affect their analyses. We compared the body length and body mass of 14 live and preserved (up to 10 years) amphibian species and found that the body length and body mass of preserved specimens significantly decreased by 7.1% and 26.7%, respectively, compared to those measurements of their live counterparts. Additionally, there was greater body length (3.6%) and body mass (6.6%) shrinkage in the order Urodela than in the order Anura, but there were no significant differences in body length and body mass shrinkage between males and females. Furthermore, preservation apparently distorted the magnitude of the intersexual and interspecific differences in body length observed in the fresh specimens. When species were compared, we found that the shrinkage was proportionately greater in longer species, while the body mass of heavier individuals shrank proportionately less than that of lighter individuals. Due to the effects of preservation on amphibian morphology, we propose parsimonious conversion equations to back-calculate the original body length and body mass of study animals for researchers working with historical data because morphological data from preserved specimens may lead to incorrect biological interpretations. Therefore, researchers must correct for errors due to preservation effects that may lead to the misinterpretation of results.

Long-term in vitro Storage Technique of Valuable Birch Genotypes and Plant Production on its Basis

2019 ◽  
pp. 57-67
Author(s):  
T.M. Tabatskaya ◽  
N.I. Vnukova
Keyword(s):  
Plant Production ◽  
High Survival ◽  
Ex Vitro ◽  
Regenerative Capacity ◽  
In Vitro Storage ◽  
Interspecific Differences ◽  
Regenerated Plants ◽  
Growing Conditions

A technique for the long-term (up to 27 years) in vitro storage of valuable birch genotypes under normal (25 °C, 2.0 klx, 16-h day and 8-h night) and low temperature (4 °C, 0.5 klx, 6-h day and 18-h night) growing conditions on hormone-free media has been described. The study explored for the first time the influence of different strategies to store the clones of Betula pubescens and B. pendula var. сarelica (6 genotypes) on the regenerative capacity of collection samples, adaptive potential of regenerated plants and plant production by the in vitro and ex vitro techniques. It was established that both storage strategies provided a persistently high survival rate (82-100%) and regenerative capacity of in vitro shoots (the multiplication coefficient of 4.2-6.3 and rhizogenic activity of 90-100%). The clones retained their characteristics of height growth under the in vitro and ex vitro conditions, and demonstrated intraclonal homogeneity and lack of signs of somaclonal variability. The plants showed substantial interspecific differences at the stage of multiplication and transfer to the greenhouse. The highest percentage of acclimated plants (75-98% depending on the clone genotype) was obtained after planting of micro plants straight in the greenhouse, which simplified the technology and made plant production less costly. long-term in vitro storage, birch, species, genotype, micropropagation, ex vitro adaptation, plant material

CHARACTERISTICS OF POST-FLIGHT MUSCLE STRENGTH AND VELOCITY DYNAMICS IN COSMONAUTS AS A FUNCTION OF WEIGHT LOADING DURING LONG-TERM SPACE MISSIONS

2020 ◽  
Vol 54 (5) ◽  
pp. 23-28
Author(s):  
E.V. Fomina ◽  
◽  
T.B. Kukoba ◽  
Keyword(s):  
Muscle Strength ◽  
Body Mass ◽  
Flight Muscle ◽  
Space Mission ◽  
The Body ◽  
Maximum Strength ◽  
Training Device ◽  
Leg Muscle ◽  
Weight Loading

Testing of 25 cosmonauts showed that the amount of resistance training weight loading in long-term space mission influences dynamics of the leg-muscle strength and velocity recovery. On Earth, the loads equal from 70 to 130 % of the body mass is sufficient for keeping up endurance and maximum strength moments of shin and thigh muscles. In the group of cosmonauts who had not used the strength training device or chosen loads less than 30 % of the body mass the leg-muscle maximum strength and thigh endurance were decreased substantially on day 4 of return and all the more by day 15 back on Earth.

scholarly journals Long-term body mass index changes in overweight and obese adults and the risk of heart failure, cardiovascular disease and mortality: a cohort study of over 260,000 adults in the UK

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Barbara Iyen ◽  
Stephen Weng ◽  
Yana Vinogradova ◽  
Ralph K. Akyea ◽  
Nadeem Qureshi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiovascular Disease ◽  
Body Mass Index ◽  
Cohort Study ◽  
Body Mass ◽  
World Health ◽  
Obese Adults ◽  
Bmi Trajectories ◽  
The Impact

Abstract Background Although obesity is a well-recognised risk factor for cardiovascular disease (CVD), the impact of long-term body mass index (BMI) changes in overweight or obese adults, on the risk of heart failure, CVD and mortality has not been quantified. Methods This population-based cohort study used routine UK primary care electronic health data linked to secondary care and death-registry records. We identified adults who were overweight or obese, free from CVD and who had repeated BMI measures. Using group-based trajectory modelling, we examined the BMI trajectories of these individuals and then determined incidence rates of CVD, heart failure and mortality associated with the different trajectories. Cox-proportional hazards regression determined hazards ratios for incident outcomes. Results 264,230 individuals (mean age 49.5 years (SD 12.7) and mean BMI 33.8 kg/m2 (SD 6.1)) were followed-up for a median duration of 10.9 years. Four BMI trajectories were identified, corresponding at baseline, with World Health Organisation BMI classifications for overweight, class-1, class-2 and class-3 obesity respectively. In all four groups, there was a small, stable upwards trajectory in BMI (mean BMI increase of 1.06 kg/m2 (± 3.8)). Compared with overweight individuals, class-3 obese individuals had hazards ratios (HR) of 3.26 (95% CI 2.98–3.57) for heart failure, HR of 2.72 (2.58–2.87) for all-cause mortality and HR of 3.31 (2.84–3.86) for CVD-related mortality, after adjusting for baseline demographic and cardiovascular risk factors. Conclusion The majority of adults who are overweight or obese retain their degree of overweight or obesity over the long term. Individuals with stable severe obesity experience the worst heart failure, CVD and mortality outcomes. These findings highlight the high cardiovascular toll exacted by continuing failure to tackle obesity.

scholarly journals Effects of Time-Restricted Feeding on Supramaximal Exercise Performance and Body Composition: A Randomized and Counterbalanced Crossover Study in Healthy Men

2021 ◽  
Vol 18 (14) ◽  
pp. 7227
Author(s):  
Joana M. Correia ◽  
Inês Santos ◽  
Pedro Pezarat-Correia ◽  
Cláudia Minderico ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Exercise Performance ◽  
Fat Free Mass ◽  
Restricted Feeding ◽  
Supramaximal Exercise ◽  
Mean Power ◽  
Post Intervention ◽  
Dietary Record

Using a crossover design, we explored the effects of both short- and long-term time-restricted feeding (TRF) vs. regular diet on Wingate (WnT) performance and body composition in well-trained young men. Twelve healthy male physical education students were included (age: 22.4 ± 2.8 years, height: 174.0 ± 7.1 cm, body mass: 73.6 ± 9.5 kg, body mass index: 24.2 ± 2.0 kg/m2). The order of dieting was randomized and counterbalanced, and all participants served as their own controls. TRF was limited to an 8-h eating window and non-TRF involved a customary meal pattern. Participants performed WnT tests and body composition scans at baseline, post-one and post-four weeks of the assigned diet. Before testing, participants were asked to fill out a dietary record over four consecutive days and were instructed to continue their habitual training throughout the study. Energy intake and macronutrient distribution were similar at baseline in both conditions. WnT mean power and total work output increased post-four weeks of TRF. Both conditions were similarly effective in increasing fat-free mass after four weeks of intervention. However, there was no correlation between change in fat-free mass and WnT mean power after TRF. TRF did not elicit any changes in WnT performance or body composition one week post-intervention. Thus, long-term TRF can be used in combination with regular training to improve supramaximal exercise performance in well-trained men.

scholarly journals Five-Year Change in Body Mass Index Predicts Conversion to Mild Cognitive Impairment or Dementia Only in APOE ɛ4 Allele Carriers

2021 ◽  
pp. 1-11
Author(s):  
Kylie R. Kadey ◽  
John L. Woodard ◽  
Allison C. Moll ◽  
Kristy A. Nielson ◽  
J. Carson Smith ◽  
...  
Keyword(s):  
Older Adults ◽  
Body Mass Index ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Body Mass ◽  
Carrier Status ◽  
Healthy Older Adults ◽  
E4 Allele ◽  
Lifestyle Risk

Background: Body mass index (BMI) has been identified as an important modifiable lifestyle risk factor for dementia, but less is known about how BMI might interact with Apolipoprotein E ɛ4 (APOE ɛ4) carrier status to predict conversion to mild cognitive impairment (MCI) and dementia. Objective: The aim of this study was to investigate the interaction between APOE ɛ4 status and baseline (bBMI) and five-year BMI change (ΔBMI) on conversion to MCI or dementia in initially cognitively healthy older adults. Methods: The associations between bBMI, ΔBMI, APOE ɛ4 status, and conversion to MCI or dementia were investigated among 1,289 cognitively healthy elders from the National Alzheimer’s Coordinating Center (NACC) database. Results: After five years, significantly more carriers (30.6%) converted to MCI or dementia than noncarriers (17.6%), p <  0.001, OR = 2.06. Neither bBMI (OR = 0.99, 95%CI = 0.96–1.02) nor the bBMI by APOE interaction (OR = 1.02, 95%CI = 0.96–1.08) predicted conversion. Although ΔBMI also did not significantly predict conversion (OR = 0.90, 95%CI = 0.78–1.04), the interaction between ΔBMI and carrier status was significant (OR = 0.72, 95%CI = 0.53–0.98). For carriers only, each one-unit decline in BMI over five years was associated with a 27%increase in the odds of conversion (OR = 0.73, 95%CI = 0.57–0.94). Conclusion: A decline in BMI over five years, but not bBMI, was strongly associated with conversion to MCI or dementia only for APOE ɛ4 carriers. Interventions and behaviors aimed at maintaining body mass may be important for long term cognitive health in older adults at genetic risk for AD.

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